1. Field
The invention relates to an organic light emitting display apparatus, and more particularly, to a bottom emission type organic light emitting display apparatus using an opposite electrode as a reflection electrode.
2. Description of Related Art
Generally, an organic light emitting display (“OLED”) apparatus has a structure in which a thin film transistor (“TFT”) and an organic light emitting device are provided so that the organic light emitting device receives an adequate driving signal from the TFT to emit light, thereby forming a desired image.
The TFT typically has a structure in which an active layer, a gate electrode, source and drain electrodes are stacked on a substrate. Therefore, when current is applied to the gate electrode through lines formed on the substrate, the current flows into the source and drain electrodes via the active layer, and simultaneously flows into a pixel electrode of the organic light emitting device, which is connected to the source and drain electrodes.
Furthermore, the organic light emitting device includes the pixel electrode, an opposite electrode facing the pixel electrode and a light emitting layer disposed between the pixel electrode and the opposite electrode. In this structure, when the current flows into the pixel electrode through the TFT as described above, an adequate voltage is formed between the opposite electrode and the pixel electrode, and thus, light is emitted by the light emitting layer, thereby an image is produced.
Here, the pixel electrode is separately provided for individual pixels partitioned by a pixel defining layer. However, the opposite electrode provided on a pixel defining layer as a single layer covers all the pixels.